This invention relates to a seal for fluid processing apparatus and, in particular, to a shaft seal arrangement for a bore of a compressor housing through which a drive shaft extends.
In an air compressor or other fluid compressor including a cylinder and a piston in a compressor housing, the housing is provided with a bore though which a drive shaft extends to transmit the driving power to the piston from any power source, such as an electric motor or an internal combustion engine.
A shaft seal in the bore of the housing is important to prevent the processed fluid from leaking.
Such a shaft seal arrangment is disclosed in U.S. Pat. No. 3,761,202, FIG. 3.
This shaft seal arrangement comprises a first seal sheet fitted into the bore of the compressor housing, a second seal sheet mounted on the drive shaft and pressed to the first seal sheet and a retainer ring fixed to the inner wall of the bore to prevent axial movement of the first seal sheet by the pressure of the second seal sheet.
The retainer ring may be a snap ring fitted into an annular groove formed in the internal surface of the bore.
According to this shaft seal arrangement, the rotation of the first seal sheet is prevented by the friction between the first seal sheet and the internal surface of the bore and the retainer ring, but rotation is not sufficiently prevented.